Softer Blended Nitrile Elastomeric Article

Abstract

An elastomeric article is formed from a blend of nitrile rubber and polychloroprene rubber. The elastomeric article can be a glove, such as a medical exam glove. The elastomeric article is softer than a conventional nitrile elastomeric article. The elastomeric article is formed from a blended rubber latex emulsion of nitrile and polychloroprene. The blended rubber latex emulsion may be free of sulfur and vulcanization accelerators.

What is claimed is: 
     
         1 . A process for making an elastomeric article, the process comprising:
 coating a surface of a mold with a coagulant solution and a release agent;   partially drying the mold coated with the coagulant solution and release agent;   immersing the partially dried mold into a blended rubber latex emulsion comprising nitrile-butadiene latex and polychloroprene to form a coagulated layer of nitrile-butadiene rubber latex and polychloroprene rubber on the mold surface;   removing the mold from the blended rubber latex emulsion;   immersing the mold containing the coagulated layer of nitrile-butadiene rubber latex and polychloroprene rubber into an aqueous bath and then drying the coagulated blend of nitrile-butadiene rubber latex and polychloroprene to form an elastomeric article on the mold;   immersing the mold containing the elastomeric article into a chlorinating bath to chlorinate an exterior surface of the elastomeric article on the mold; and   removing the elastomeric article from the mold by inverting the elastomeric article such that the chlorinated exterior surface of the elastomeric article forms an interior surface of the elastomeric article.   
     
     
         2 . The process of  claim 1 , wherein the blended rubber latex emulsion has a total latex solids content of between about 15 percent and about 30 percent, by weight. 
     
     
         3 . The process of  claim 1 , wherein the blended rubber latex emulsion has a ratio of nitrile rubber to polychloroprene rubber in a range from about 50:50 to about 95:5. 
     
     
         4 . The process of  claim 1 , wherein coagulation of the blended rubber latex emulsion to form the elastomeric article is further accelerated by a crosslinker, wherein the crosslinker is a trivalent crosslinker. 
     
     
         5 . The process of  claim 4 , wherein the trivalent crosslinker is a metallic oxide that forms bonds with carboxyl groups of the nitrile rubber. 
     
     
         6 . The process of  claim 1 , wherein the blended rubber latex emulsion is free from a dithiocarbamate accelerator, zincediethyldithiocarbamate (ZDEC), zinc mercaptobenzothiazole (ZMBT), diphenyl guanidine (DPG), or a combination thereof. 
     
     
         7 . The process of  claim 1 , wherein the elastomeric article is a glove. 
     
     
         8 . The process of  claim 4 , wherein coagulation of the blended rubber latex emulsion to form the elastomeric article is further accelerated by a metallic salt, wherein the metallic salt includes nitrate, sulfate, or chloride salts of calcium, aluminum, or zinc, or a combination thereof. 
     
     
         9 . The process of  claim 8 , wherein the metallic salt is a divalent compound. 
     
     
         10 . The process of  claim 8 , wherein the metallic salt is zinc oxide. 
     
     
         11 . The process of  claim 1 , wherein the blended rubber latex emulsion is free from sulfur. 
     
     
         12 . A process for making an elastomeric article, the process comprising:
 coating a surface of a mold with a coagulant solution and a release agent;   immersing the mold into a blended rubber latex emulsion comprising nitrile-butadiene latex and polychloroprene to form a coagulated layer of nitrile-butadiene rubber latex and polychloroprene rubber on the mold surface;   removing the mold from the blended rubber latex emulsion;   immersing the mold containing the coagulated layer of nitrile-butadiene rubber latex and polychloroprene rubber into an aqueous bath and then drying the coagulated blend of nitrile-butadiene rubber latex and polychloroprene to form an elastomeric article on the mold;   immersing the mold containing the elastomeric article into a chlorinating bath to chlorinate an exterior surface of the elastomeric article on the mold; and   removing the elastomeric article from the mold by inverting the elastomeric article such that the chlorinated exterior surface of the elastomeric article forms an interior surface of the elastomeric article.   
     
     
         13 . The process of  claim 12 , wherein the blended rubber latex emulsion has a total latex solids content of between about 15 percent and about 30 percent, by weight. 
     
     
         14 . The process of  claim 12 , wherein the blended rubber latex emulsion has a ratio of nitrile rubber to polychloroprene rubber in a range from about 50:50 to about 95:5. 
     
     
         15 . The process of  claim 12 , wherein the blended rubber latex emulsion comprises a divalent metal oxide and a trivalent crosslinker. 
     
     
         16 . The process of  claim 12 , wherein the blended rubber latex emulsion is free from a dithiocarbamate accelerator, zincediethyldithiocarbamate (ZDEC), zinc mercaptobenzothiazole (ZMBT), diphenyl guanidine (DPG), or a combination thereof. 
     
     
         17 . The process of  claim 15 , wherein coagulation of the blended rubber latex emulsion to form the elastomeric article is further accelerated by a metallic salt, wherein the metallic salt includes nitrate, sulfate, or chloride salts of calcium, aluminum, or zinc, or a combination thereof. 
     
     
         18 . The process of  claim 12 , wherein the blended rubber latex emulsion is free from sulfur. 
     
     
         19 . The process of  claim 12 , wherein the elastomeric article is a glove. 
     
     
         20 . A process for making an elastomeric article, the process comprising:
 coating a surface of a mold with a coagulant solution and a release agent;   immersing the mold into a blended rubber latex emulsion, wherein the blended rubber latex emulsion comprises a divalent metal oxide and a trivalent crosslinker;   removing the mold from the blended rubber latex emulsion;   immersing the mold into an aqueous bath and then drying blended rubber latex emulsion to form an elastomeric article on the mold;   immersing the mold containing the elastomeric article into a chlorinating bath to chlorinate an exterior surface of the elastomeric article on the mold; and   removing the elastomeric article from the mold by inverting the elastomeric article such that the chlorinated exterior surface of the elastomeric article forms an interior surface of the elastomeric article.